Body than in One of Five or Six Months In a Faetus of Nine Months it almost fills the Interstice which the Lungs after the Birth begin to take up in the Upper-part of the Thorax The Thymus after the Birth gradually decreases except the Upper-part of the Cavity in the Thorax is Capacious enough for its Reception as appear'd in an Anatomical Subject I lately Dissected of Thirty Years of Age in whom the Thymus was very large I must confess I never yet met with a Subject tho never so Old in whom the Thymus was wanting In those Bodiâ—â— the Thymus is less than ordinary we find the Subclavian Glands those of the Internal Jugular Veins and the Glandule Thyraidam larger as they lately appear'd in a Boy of about Eight Years of Age. In Women the Thymus and Thyroid Glands are larger than in Men but the Subclavian Glands are less by reason the Claviculae in Women are straight and shorter than those of Men whence a much less Interstice is frain'd for entertaining those Glands I have more than once found the Lymphe-Ducts fill'd with Wax which Arise from the Thymus and empty themselves into the Upper-part of the Thoracick-Duct by Injecting that Duct by the Vesica Chyli See App. Fig. 12. D. From what has been abovesaid it appears the Thymus bears a Proportion to the Head whether in the Faetus or in Bodies before they become Adult which we conceive is in order to receive a Proportionable Quantity of Lympha deriv'd from thence And as the Subclavian Glands of Women are less than those of Men so the Thyroide Glands and Thymus are larger Hence also it appears the Thymus is a Lymphatick Gland and Varies its Magnitude according to the Quantity of the Lympha that is necessarily transmitted thro' it from the Superior Parts or as the Neighbouring Lymphatick Glands do more or less transmit their Lympha to it Besides this common Office of the Thymus whether in the Faetus or Adult it has another Use which was first suggested to Me by Injecting a Liquid into the Thoracick-Duct when finding it not only fill the Lymphe-Ducts of the Thymus but the Thymus it self was Extended with it The like Observation I since found was made by the Expert Anatomist Dr. Tyson some Time since whence I conceive the Thymus and its Lymphe-Ducts are Diverticula to the Chyle when too great a Quantity is pressing forewards towards the Subclavian Vein I know it may be Objected that the Valves of the Lymphe-Ducts oppose this contrary Course of Liquours in them but repeated Observations convince me that not only these Lymphe-Ducts of the Thymus which are large and have very few if any Valves as appears by their being Injected with Wax but those of the Loins and their Glands from whence they Arise are frequently fill'd with Chyle when no Compress is made on the Thoracick-Duct Hence it is a Milky Liquor has been commonly found in the Thymus but more frequent in that of a Pâ—tus than iâ— an Adult and that not only because the Thymus and its Lymphe-Ducts are much larger Proportionably in the former State or Faetus but the bended Position of the Thoracick-Duct of the Fetus in Vterâ— renders the Ascent of the Chyle by that Duct more liable to Regurgitate by the Lymphe-Ducts of the Thymus H H The Fore-part of the Diaphragma free'd from the Cartilaginous Endings of the Ribs and Pinn'd up THE TWENTY-SECOND TABLE Fig. 1. THE Heart with Parts of the Trunks of the great Veins and Arteries cut off A A The proper Membrane of the Heart a Portion of which is Rais'd and hangs Down B B The Left Side of the Heart adorn'd with in Coronary Vessels C ψ Part of the Right Auricle of the Heart C The Left Auricle on the Basis of the Heart D The Cone of the Heart E The Vena Cava which conveys the Refluent Blood from the whole Field of the Body into the Right Auricle of the Heart when the Heart iâ— iâ— Systole whence the Blood is again transmitted into the Right Ventricle of the Heart when it is in Diastole So that when the Auricles of the Heart are in Diastole or Relaxation they are fill'd with Blood and the Heart it self is in Systole or Contraction and Vice versa when the Heart is in Diastole the Auricles are in Systole F The Arteria Pulmonalis or Vena Arteriosa which carries the Blood from the Right Ventricle of the Heart into the Lungs G The Vena Pulmonica or Arteria Venosa which conveys the Refluent Blood from the Lungs into the Left Auricle and Ventricle of the Heart not unlike the Vena Cava c. H The Arteria Magna Arising out of the Left Ventricle which conveys the Mass of Blood from the Heart thro' the Field of the Body from whose capillary Extremities the Veins are continued as appears by a Microscope in the transparent Parts of living Animals See App. Fig. 4. and 5. Fig. 2. The Heart divested of its External Membrane and Carnous Fibres after Boyling so that the Disposition of the Subjacent Fibres may appear The way of preparing the Heart to exhibit this Disposition of its Fibres may be practis'd after the following Manner The Heart with Portions of the Trunks of the large Blood-Vessels being taken off the Blood as well within its Ventricles as Blood-Vessels being evacuated then with Tow or Pieces of Rags fill the Ventricles Auricles and large Vessels on the Basis of the Heart the Mouths of the large Blood-Vessels being stitch'd up least their Contents should be Extruded by the Contraction of the Heart in Boyling This done Boyl it according to its Bulk if it is the Heart of an Ox c. Boyl it Four or Five Hours if of a Man One or Two N. B. This Figure is Printed reverst A A Sinus plac'd between both Ventricles in which a large Trunk of one of the Coronary Arteries is convey'd B The Cochleated or Oblique descending Order of Fibres of the Left Ventricle of the Heart C The External and Oblique descending Order of Fibres of the Right Ventricle which decussate the former or Subjacent Fibres in Acute Angles D Part of the Arteria Pulmonalis E The Aorta ee The Trunks of the Coronary Arteries F The Right Auricle G The Left Fig. 3. A The Sinus above mention'd between the Ventricles B The Tortuous Disposition of the Fibres of the Right Ventricle C Those of the Left The Heart consists chiefly of divers Strata of Oblique descending Fibres the External passing more straight or less Contorted than the Internal whence it happens that the External Fibres are seen to Decussate the Internal with Acute Angles the former Arising from the Basis of the Heart at the Roots of the Blood-Vessels and End in the Cone the later Arise from the same Place and Terminate either in the ' Parietes of the Ventricles or Columnae Carneae Fig. 7. g g from which divers Tenditious Filaments are continued to the Lower-parts of the Tricuspid
and Mitral Valves D The Aorta divided between its Origin from the Heart and Valves and reclin'd to One Side hanging by its Two◠Coronary Arteries Exprest Fig. 2. e e. e e The Three Semilunary Valves of the Aorta which hinder a Return of the Blood into the Left Ventricle when the Heart is in Diastole Fig. 4. The Concourse of Fibres near the Cone of the Heart as they appear after a Transverse Section Fig. 5. Some Fasciculi of Fibres of the Left Ventricle of the Heart A B The Two Tendinous Extremities of the Oblique Fleshy Fibres Exprest Fig. 2 3. C The Fleshy Parts of the Fibres between the Two Tendons D The Collateral Fibres which appear in dividing the last mention'd Fasciculi Nor are these any other than Parts of the Fibres of the divided Fasciculus and lay Parallel to each other according to their length The Blood-Vessels and Nerves passing between these Fibres make a Reticular Appearance when divided as here Exprest Fig. 6. The Right Auricle and Part of the Basis of the Heart A A The Right Auricle expanded B B B The Three Tricuspid Valves Two of which are extended by Pinning out their Tendons deriv'd from the Columnae Carneae See Fig. 7. g g Fig. 10. A Inferior The Office of the Auricles is to receive Part of the Refluent Blood whilst the Heart is in Systole and to discharge that Blood again into the Ventricles of the Heart when it is in Diastole so that the Auricles of the Heart seem as Diverticula to the Blood in its passing into its Ventricles else a Repercussion of the Blood in the Veins would necessarily happen in the Systole of the Heart which would prevent the regular Influx of the Blood to the Ventricles Fig. 7. The Heart with its Left Ventricle Open'd A The Inside of the Vena Pulmonalis B The Aorta in like manner Open'd C C The Septum Cordis which divides the Right Ventricle from the Left D The Left Auricle intire which in Humane Bodies is very little as appears by this Figure and the Trunk of the Pulmonick Vein very large d The Trunk of the Arterìa Pulmonica cut off e e Two of the Three Semilunary Valves at the Beginning of the Arteria Magna which hinder the Reflux of the Blood when the Heart is in Diastole in which Action they are Exprest Fig. 3. e e. f f The Two Mitral Valves in the Pulmonick Vein which prevent the Blood repassing that Vessel when the Heart is in Systole g g The Carneae Columnae compos'd of Muscular Fibres deriv'd from those of the Sides of the Heart whençe divers small Tendinous Filaments do Arise and are faltned to the Inferior Limbus of the Mitral Valves by which means those Valves are drawn down towards the Cone of the Heart and prevent the Blood from passing out again that way when the Heart is in Systole I know Dr. Lower in his Accurate Book De Corde Supposes that these Mitral and Tricuspid Valves are Relax'd in the Systole of the Heart and by their Rising up stop up the Passages of the Veins But if the Structure of the Heart and these Parts are Attentively consider'd in a large Animal as in an Ox c. it will appear reasonable to conceive that these Mitral and Tricuspid Valves are rather drawn down than suffer Extrusion upwards nor need Nature have been at any trouble in making those Valves at the Orifices of the Veins any otherwise than the Reverse of the Semilunary Valves of Arteries if as the Expert Dr. Lower Supposes they are driven up and Extended like a Sail with Wind when the Heart is in Systole but by fastening those Tendinous Fibres to the Lower-parts of those Tricuspid and Mitral Valves which are of a Conical Figure seems to me to be an Argument that they cannot suffer such Extension upwards without letting some Part of the Blood repass them in the Systole of the Heart Besides there must constantly a considerable Part of the Blood remain in the Ventricles of the Heart if those Valves are so dispos'd in its Systole which I think the Dr. himself seems no where to conceive but on the contrary the Ventricles of the Heart are with great Strength adequately Comprest in it's Systole for which End the Insides of its Ventricles are compos'd of divers Fleshy Columns between which divers Intersticia necessarily Result that are elegantly Exprest in this Figure by which means the Ventricles are more exactly Closed in their Systole than they could have been had they been smooth Fig. 8. The Heart with its Right Ventricle Open'd A The Inside of the Right Auricle of the Heart as it appears when Open'd and Pinn'd out B The Left Auricle Intire C The Coronary Blood-Vessels of the Heart from these particularly from the Arteries Spring those of the Auricles and large Blood-Vessels of the Heart as the Accurate Ruysch describes them in his Anatomical Epistles Pag. 15. The Nerves of the Heart Spring from the Eighth Pair and Intercostal Nerves a particular Description of which may be found in Dr. Lower's Book De Corde and Vieussenius Nervographia D Part of the Right Ventricle of the Heart Open'd E A Portion of the Vena Arteriosa or Arteria Pulmonalis Divided and Expanded f f f The Three Valvulae Sigmoides or Semilunares which oppose the Return of the Blood from the Lungs by the Arteria Pulmonica into the Heart when it is in Diastole Fig. 9. A A The Heart cut Transversely B That Part of it next its Basis. C That next its Cone D D The Right Ventricle of the Heart E The Left F The Septum Cordis or the Partition between the Two Ventricles of the Heart G G A Stylus put thro' the Vena Cava into the Right Ventricle of the Heart H H Another passing from the same Ventricle thro' the Arteria Pulmonalis I I A Stylus in the Left Ventricle of the Heart passing out at the Arteria Magna K K Another Inserted into the same Ventricle by the Vena Pulmonica Fig. 10. A Inferior A Portion of the Columna Carnis of One of the Ventricles of the Heart cut off See Fig. 7. g g in Situ B The Tendinous Fibres deriv'd from the Fleshy Column and fastned to the Inferior Margin of One of the Tricuspid Valves A A Superior Portions of the Tricuspid Valves Fig. 11. The Coronary Blood-Vessels of the Heart as they appear on its Surface when Injected after Drying the whole Heart A A The Arteries fill'd with Mercury fix'd with Tin B B The Veins Extended with Wax Fig. 12. A Portion of the Vena Pulmonalis next the Basis of the Heart A A Parts of the Mitral Valves Pinn'd out by their Tendons Fig. 13. The Inner Surface of a Portion of the Arteria Magna cut off at the Basis of the Heart when Divided and Expanded A A A A The Three Semilunary Valves well Exprest when Pinn'd out One of them being cut thro' in its Middle in dividing the Great Artery Fig.
the Arteries of a Humane Foetus Injected with Wax and Display'd after Dissection 1 The Aorta or Arteria Magna cut from its Origin at the Orifice of the Left Ventricle of the Heart 2 The Trunk of the Great Coronal Artery of the Heart Arising from the Beginning of the Aorta the Rise of the Lesser Coronal Artery not Appearing in this Position of the Arteria Magna 3 The Canalis Arteriosus Fill'd with Wax by Injecting it into the Aorta This Arises from the Upper Part of the Trunk of the Pulmonick Artery near its Two Ramifications which pass into the Lungs and after an Oblique Descent under the Beginning of the Aorta Empties it self into the Upper Part of its Descending Trunk as here Exprest 28. Besides this Communication between the Right Ventricle of the Heart of a Foetus and Arteria Magna there is another call'd Foramen Ovale by which Part the Blood at its Entrance into the Right Ventricle passes into the Pulmonick Vein and the Left Ventricle of the Heart thence to the Aorta Hence it Appears That the Blood which Flows into the Right Ventricle of the Heart of the Foetus Passes immediately by the Canalis Arteriosus to the Arteria Magna as well as the Blood of the Left Ventricle which is Receiv'd immediately from the Vena Câ—â—a or Right Article of the Heart into the Pulmonick Vein and Left Ventricle So that the Blood in the Foetus which Runs into the Right Ventricle passes immediately to the Aorta by the Systole of the Heart as well as the Blood of the Left Ventricle Not do's any Part of the Blood of the Right Ventricle pass into the Left Or any Blood of the Left Ventricle first pass the Right as in the Adult Hence the Heart in the Foetus may be said to have but One Ventricle in Effect since the Blood which passes One do's not come into the Other before it arrives at the Aorta After the Birth when the Infant has Receiv'd Air into the Lungs and their Vesciculae remain Distended and the Ramifications of the Pulmonick Arteries and Vein consequently are more Display'd the Blood thâ—â— begins to pass their Extremities more freely than before and the Arterious Chanel at length becomes neglected as well as the Foramen Ovale the Former becoming a Ligâ—â—â—â— and the Latter Closing up The too early Occlusion of these Passages in Children often produces many Disorders as Inflammation of Divers Parts of the Head Neck and Lungsâ— in which Cases Bleeding is of great Use Of this I have met with many Inâ—â—â—nces in the Dissection of Children I have often found the Foramen Ovale open in the Adult The Canalis Arteriosus for what I have observ'd closes sooner than that Foramen 4 4 The Subclavian Arteries Arising from the Arteria Magna to which the Axillary Arteries and those of the Arms 23 23 are conâ—â—'d 5 5 The Two Carotide Arteries Arising from Aorta between the Subclavian Arteries 6 6. The Two Vertebral Arteries Arising from the Subâ—levâ—culae which pass thro' all the Transverse Processes of the Vertebrae of the Neck from whence they are freed 7 7. The Arteries which Convey Blood to the Lower Part of the Face Tongue Adjacent Muscles and Glandules 8 8. The Trunks of the Temporal Arteries Spring from the Carotides and giving Branches to the Parcâ—ide Glands 9 9. as well as the Temples 10 10. also to the Neighbouring Muscles Hairy-Scalp and Forehead 11 11. The Occipâ—tal Arteries whose Trunks pass close by the Mammiâ—oâ—â— Process and are Distributed on the Hinder Paâ—â— of the Hairy-Scalp where they are Inosculated with the Branches of the Temporal Arteries 12. Diâ—ers Arteries which carry Blood to the Fauces Gaâ—gaâ—con and Muscles of those Pâ—â—â—â— 13 13. The Contortions of the Carotid Arteries as they pass the Basis of the Skull to the Brain 14 14. Those Parts of the Carotid Arteries where they pass by each Side of the Solla Tâ—â—ica where Diâ—eâ—â— Small Branches do Arise from them and help to Compose the Rete 〈◊〉 which is more conspicuous in Quadrupedes than Men. 15 15. The Contortions of the Vertebra Arteries as they pass the Transverse Processes of the First Vendâ—â— â—â— the Neck towards the Great Foramen of the Os Occiputis I have more than once taken Notice That the Cavities of these Arteries where they are Conâ—eâ—â—ed have been Larger than their Inferior Trunks whereby the Impetus of the Blood must necessarily be very much Lessen'd as well as by their Contortions only In Quadâ—â—pedes the Angles of these Contortion of the Arteries of the Brains are more Acute which in them is the more Necessary to Lessen the Force of the Blood at their Extremities by Reason of the Horizontal Position of their Trunks 16. The Vertebral Arteries where they Ascend on the Medulla Oblongata towards the 〈◊〉 Protuberance or Poâ—a Varâ—â— 17 17. The Communicant Branches between the Carotid and Vertebral Arteries in this Subject somewhat Larger than we Commonly find them 18 18. The Ramifications of the Arteries within the Skull the Larger Trunks of which lie between the Lobes of the Brain and in its Sâ—â—â—i From the Extremities of these Arteries of the Brain are Continu'd its Veins whose Trunks vary much in their Position from the Arteries They Entring the Brain at its Basis and Distributing themselves as above noted whereas the Trunks of the Veins are Extended on the Surface of the Brain and Discharge their Blood into the Longitudinal Sâ—râ—s Nor do's the Veins of the Brain Accompany its Arteries at their Ingress as in other Parts Or the Arteries and Vein of the Dura Meter pass the same Fâ—ramen in the Basis of the Skull 19 19. The Arteries of the Larynx Thyroid Glandules and Adjacent Muscles and Parts Arising from the Subclavian Arteries 20 20. Others Arising near the Former which convey Blood to the Muscles of the Neck and Scapulâ— 21 21. The Mammariae which Arise also from the Subclavian Arteries and Descend on the Cartilages of the True Râ—bs Internally about Half an Inch distant on each Side the Or Pectoris or Sâ—rmâ—n Some Branches of these pass thro' the Pectoral as well as iâ—â—â—costal Muscles and give Blood to the Mammae where they meet with some Branches of the Intercostal Arteries to which they are Inosculated These Maminary Arteries join with the large Trunks of the Epigastricks 57 57. also by which Means the Impetus of the Blood in Integuments of the Abdomen is carry'd on with more Force the Exâ—â—â—es of the Intercostal and Lumbal Arteries do also Inosculate with each other as well as with These 22 22. The Arteries of the Muscles of the Os Humeri and some of those of the Scapulâ— 23 23. Those Parts of the Large Trunks of the Arteries of the Arms which are liable to be Wounded in Opening the Vena Basilica or Innermost of the Three Veins in the Bending of the Cubit See Fig. 1. of this Appendix between 26. and m where the Precise Progress of
and from the Mixture of these two Juices is compounded a proper Menstruum by which the Parts of the Aliment are dissolved and receive their first Transmutation within the Body In this Action which is a Dissolution of the Texture of the Alimentary Mass the Aerial Parts included in its Pores now escape from their former Prisons and being rarified distend the whole Body of the Stomach and this I take to be the true Reason why most Men have less Appetite at some distance of Time viz. when this Intumescence is made than immediately after they cease from Eating From the same Cause arise frequent Eructations great Inflation from divers Meats such as Old Pease Cabbage Roots Herbs and other Vegetables which very much disturb decay'd debilitated Stomachs I am apt to suspect the Stomachick Menstruum may excite an Intestine motion of the Particles of the Mass in Digestion which yet I do not think fit to call Fermentation fearing so bold a Term may mislead us into a False Idea of a greater Conflict than really happens The Intumescence or Dilatation of the Stomach has two Effects First to compress the Gall Bladder and Pancreas and oblige their Ductus Excretorii to spue out their Contents into the Duodenum next to retard the Refluent Blood and by this means dispose the Muscular Fibres of the Ventricle to a Contraction The Reason of this last Hint will appear by what we have offer'd concerning Muscular Motion in the Introduction to our Myotomia Reformata For the Cause of Hunger which is an observable Phaenomenon belonging to this part I conceive it to be an Irritation of the Stomach arising from a copious Quantity of this Menstruum when it wants Matter to act upon This conjecture seems more probable since it is Natural to discharge the Spittle out of the Mouth which comes into it at that Time rather than suffer it to descend into the Stomach and we may perpetually observe a depraved Appetite does follow a Vitiation of the Saliva as in Scorbutick Habits Salivations by Mercurial Medicines and such like Cases When the Mass is sufficiently prepar'd and reduced to a Pultaceous Consistence the Stomach by the help of its Muscular Fibres contracts it self and expels its Contents thro' the Pylorus into the Duodenum where the Digested Mass is mixed with the Bile and Pancreatick Juice forced to discharge it self here as was just now described which Volatilize Subtiliate and Separate the more Fluid and Fine Parts of the Aliment from the more Impure and Gross and here it is that Chylification is first made perfect Now the Bile abounding with Lixivial Salt is apt to intangle with the grosser Parts of the Chylaceous Mass and its Saline Quality not only cleanses the Cavities of the Guts from the Mucus Excreted by their Glands App. Fig. 40. to smear their Inmost Coat and defend the Ostia of the Lacteal Vessels from being injured by Extraneous Bodies which may happen to pass that way but Stimulates the Intestines in their Peristaltick Motion The Peristaltick or Wormlike Motion of the Guts being thus Accelerated by the Acrimony of the Bile the Contents of the Intestines are carried on and the Thinner and more Fluid Parts fitted for the Pores of the Lacteal Vessels is absorbed by them and the Thicker move on more slowly till by the many Stops they meet with in the Connivent Valves all the Chyle is at length absorbed and the Remains being meerly Excrementitious are only fit to be excluded by Stool This Vermicular Motion of the Guts is perform'd by the Alternate Contraction of their Longitudinal and Transverse Fibres App. Fig. 39.40 which at the same Time convey the Digested Mass thro' the Intestinal Tube and express the Chyle into the Orifices of the Lacteal Vessels adapted to receive it whose Progress from the Intestines till it is discharged into the Mass of Blood next presents it self to our Consideration By the reciprocal Action of these differing Fibres and the Apposition of the Connivent Valves Tab. 39. Fig. 2. the Chyle is forced into the Lacteal Vessels Tab. ib. Fig. 1. and hence it is we cannot make any Fluid pass from the Cavity of the Guts into the same Vessels when the Peristaltick Motion ceases A farther Use of the Contraction of these Muscular Fibres is to Accelerate the Chyle in its Progress till the Lympha derived from the Arteries of the Guts joyn with it which is done before it leaves the External Surface of the Intestines by this Addition the Chyle is diluted and assisted in its Progress towards the Mesenterick Glands in the Cells of which it is a Second Time Mixed with a Juice or Lymphatick Liquor there Secreted from the Arteries and so carried on to the Vasa Lactea secundi Generis These Vessels resembling Pipes convey the Chyle from hence all emptying themselves into the Common Receptacle or Cistern the happy Discovery of which we owe to the Observation of Mons. Pecquet It is here the Lympha returned from the Inferior Limbs and adjacent Parts is mixed with the Chyle App. Fig. 11. which not only serves to dilute but promotes its Ascent thro' the Thoracick Duct Fig. ib. to the Lest Subclavian Vein Fig. ib. where this Channel empties its Contents into the main Current of the Blood If we consider in this Duct its several Divisions and Inosculations resembling the Veins of the Testicles its numerous Valves looking from below Upwards its advantageous Situation between the Great Artery and Vertebrae of the Back together with the Ducts discharging their Refluent Lympha from the Lungs and the other Neighbouring Parts we shall find all conduce to demonstrate the utmost Art of Nature used in furthering the Steep and Perpendicular Ascent of the Chyle which Beautiful Order is Represented App. Fig. 11. and cannot but equally Create in us Delight and Admiration Having traced this Animal Juice to its Reception into the Blood with which it is at last Circulated and Assimulated we shall proceed to the Blood it self whose Circular Motion the various Artifices of Nature for adjusting the Proportions and other subordinate Contrivances the Manner and Cause of the Contraction of the Heart and Arteries Respiration with the whole Theory of the Lympha and Glandular Secretion in the Order of Nature follow The Refluent Blood in the Upper and Lower Trunk of the Vena Cava meeting in the Right Auricle of the Heart is thence expelled by its Contraction into the Right Ventricle when the Heart is in its Diastole but by its Systole or Contraction it is thence driven into the Arteria Pulmonaris from whose Capillary Vessels it passes into the Extremities of the Vena Pulmonaris and thence returning is discharged into the Left Auricle and Ventricle of the Heart From whence it is again by the Systole driven into the Aorta by whose Branches it is convey'd thro' the whole System of the Body But when it arrives in the Capillary Arteries it do's not stop there but passes into the like
Capillary Veins and from thence into the greater Branches next into the Trunk of the Vena Cava and so into the Right Ventricle again In the mean time the Three Tricuspid Valves in the Right Tab. 22. Fig. 6. and the two Mitral Valves Tab. ead Fig. 12. in the Left Ventricle of the Heart oppose its return into the Vena Cava and Vena Pulmonaris and the Semilunary Valves of the Arteria Pulmonaris Tab. ead Fig. 14. and Aorta Tab. ib. Fig. 13. prevent its Reflux into the Ventricles The Structure and Position of which Membranes are sufficient alone to lead all Observing Men into a compleat Knowledge of its Motion and Progress The Circular Motion of the Blood was first Explain'd and the whole Demonstrated in a Treatise expresly Writ upon that Subject and Published in the Year 1628. by our Learned and Ingenious Dr. Harvey To omit all disputes here how far this was known to Cesalpinus Columbus Servetus or any of the Anatomists or Virtuoso's of the last Age. But the Manner how this Animal Liquor is transmitted from the Arteries to the Veins has remained hitherto a Secret and afforded Matter of Controversie Some pretend this is done by some blind Imperceptible Meatus in the Carnous Parts and perplex themselves to give Irrational and Chimerical Accounts which we shall not here lose Time to enumerate or refute But the late great Improvement of Microscopes has put an end to all these uncertain Conjectures by discovering to our Naked Eye that the Veins and Arteries are but one continued inflected Tube and the Blood passes from one to the other in an uninterrupted Current which Unity of the Blood-Vessels by a Parity of Reason we infer extends to the whole System and will hardly be questioned by those who consider the Prompt Passage of Mercury and other injected Liquors from the Arteries to the Veins or see the Globules of Blood passing these Angustia and reverting with incredible Rapidity in the Fins of Fishes App. F. 4 5. which curious Discovery ought not to be reputed the least Advancement which this Part of Natural History has receiv'd The great Engine which sets all this Motion on Foot is the Heart Tab. 22. Fig. 9. by whose repeated Elastick Contraction the Blood is driven to the remotest Parts thro' the Arterial System App. Fig. 3. and forced to continue its Motion back thro' the Venous Channels This Elastick Force is primarily seated in its own Muscular Fibres whose Spiral Contortion Tab. 22. Fig. 2 3. is very well described by Dr. Lower in his Book De Corde but the Pendulous Position and the Fibres which compose its Great Arteries i. e. the Pulmonaris and Aorta assist very much and the Heart taken out of the Body and held up by the Arteries will continue the least gentle Motion imprest on it for a considerable Time which Effect can only be ascribed to the Elasticity of the Arterial Trunks by which it is suspended The Heart is the immediate Instrument but what is the Vis Motrix which forces its Fibres to a Contraction is a far greater Difficulty and one of the most Abstruse Inscrutable Mysteries of Nature It is in this respect our Bodies differ from Artificial Machines the Former having in themselves a perpetual Principle of Motion which the Latter by no Invention of Men can arrive at In my Opinion the Heart of an Animal bears a great Analogy to the Pendulums of those Artificial Automata Clocks and Watches whilst its Motion is perform'd like that of other Muscles the Blood doing the Office of a Pondus The Observation of the Curious Mons. Peyer in Parergo Septimo seems to favour this Opinion who tells us He has with Pleasure seen the Heart renew its Contraction by blowing into the Thoracick Duct when the Parts have began to grow stiff after Death The like Motion of the Heart I have more than once observ'd to be restor'd by blowing into the Veins of a Dog and pouring warm Water on it or applying the Palm of the Hand not long after its Cessation Besides the Quantity doubtless the Quality of the Blood has a Share since all Distempers which alter the Mass at the same Time create a Hurry and Disorder in its Motion To explain the Action of the Blood in this Case and the Influence it has over the Motion of the Heart we must consider its Nature Constituent Parts and the Alterations it is disposed to receive This Animal Fluid consists of Two Parts Serous and Globular The Distinction of these Parts of the Blood is evident to the Naked Eye after its Stagnation in any Vessel but is clearly evinced by the Microscope in its Circulation thro' the Tails and Fins of Fishes and other Transparent Parts in the same manner as is Represented Appendix Fig. 4 5. where the Globules seem to Swim in the Serum in this state of Mixture Now the Blood being in this manner a Heterogeneous Liquor Compos'd of Particles of various Magnitude and Figure must be subject to an Intestine Motion but the great Rapidity of its Current thro' the Arteries and the Angustiae in the Extremities of the Blood-Vessels not admitting any Retrograde Motion to be there made it is deferr'd till it arrives in the Great Veins where its Progress is retarded and the Room more spatious and the Intestine Motion there Commences which arises to a Greater or Less Height as the Blood is more or less Charged with Incongruous Parts The Alteration which the Blood by this means receives has no inconsiderable Share in the Heart's Contraction and tho it be not the prime efficient Cause yet we cannot deny but that it is Partial and Incitative as appears in Fevers and several other Distempers where the whole Mass is Accelerated and the Pulse more frequent Besides all these Causes the Brain by its Nervous Trunks sent to this Part which are very Thick and Tense yet lie very loose contributes much to this Action And here we may observe not only these of the Heart but the whole System of Nerves which serve the Viscera in the Thorax and Lower Belly have their Propagines very Numerous and Tense notwithstanding which they lie Loose or Free in their Progress from the Brain to their respective Parts both which concur in disposing them to Receive and Retain all Impressions from their Extremities This Faculty beginning to Exert it self even while the Foetus is in Vtero grows Familiar and Natural and from this early Habit and Practice of the Infant they after perform their Duty Sleeping or Waking without the least Advertence but this by the by And now if what has been Noted shall be thought sufficient to give ground to Hope Future Enquiries may discover more Adequate Causes of this great Phaenomenon we have obtained our Desire and shall leave these Hints to be improv'd by Men of more Industry and Leasure Before we leave this Subject we must not omit to Remark some Observable Artifices of Nature for the better carrying
on the Circulation The First is the Valves placed in the several Divarications of the Veins between their Capillar Extremities and Larger Trunks These are Membranes proceeding from the inner Coat of the Vessels in the Form of a Crescent or C. which was the Ancient Greek Sigma and are generally Double with their Concavity looking towards the Heart and readily give way to the Current of the Blood thither as is Represented Tab. 23. F. 7. But if by its Weight or any other Cause the Blood should Revert they oppose it and being Distended prevent its Return from the Great Trunks of Veins to the Lesser and at the same time hinder the Superincumbing Blood from pressing on the Inferior concerning which consult Tab. 23. Fig. 6. Another Considerable Artifice in Nature is the Conveying great Quantities of Refluent Blood from several Parts of the Trunk by particular Channels instead of discharging it by the next and most immediate Passage into the Neighbouring Current Dr. Lower has well Observ'd that the Heart is not placed in the Center of the Body but inclines to its Upper Part which Position is necessary to Drive the Blood in its Systole to the Head with more Force then is required to make it Descend to the Feet to which its own Weight and Fluidity do's not a little Conduce Now the Heart being seated so near the Upper Part as that Two Parts in Three of the whole Fabrick appear to be below it there must be a like Inequality of Blood sent to the Inferior Parts to that which Ascends to the Superior And this we see Confirm'd by comparing the Diameter of the Blood-Vessels Descending with the Ascending the Former being much Larger then the Latter This great Disproportion of Blood in the Upper System to that of the Lower seems to threaten a great Disturbance in the Animal Order but is prevented by the Provident Care of the Author of Nature in the Manner we are now about to Describe The Intercostal Arteries App. F. 3. which arise from the Lower System are accompanied with Veins that Return the Blood they Exported which do not enter into the next Large Trunk according to the ordinary Process of Nature in other Parts but are all United into One Channel and sometimes Two which Ascends by the Side of the Aorta and Empties it self into the Descending Trunk of the Vena Cava there Discharging all its Refluent Blood which had it been Inserted into the Ascending Trunk it must have added so great a Weight that the Blood could not have past up to the Heart which it now easily do's Beside these the Mammary Veins likewise Empty themselves into the Subclavian so that all the Blood Arising from the Parietes of the Thorax the Back and its Muscles as well as those of the Scapulae returns again to the Heart by the Upper Trunk of the Vena Cava tho' it was sent thither from the Lower Trunk of the Arteria Magna Another Contrivance of this Nature is Observable in the Vena Porta which Receives the Blood from the Stomach Omentum Spleen Pancreas Guts and Mesentery sent thither by the Coeliack and Mesenterick Arteries which large Quantity had it Enter'd into the Vena Cava immediately below the Liver or Kidneys its Weight so far beneath the Diaphragm must have Hindred its Ascent wherefore the Vena Porta not unlike the Azygos of the Thorax before Noted carries up all the Blood by another Channel and Discharges it into the Extremities of the Vena Cava within the Liver where it is Diluted and Propell'd by the Refluent Blood from the Splenick Vein and afterwards assisted in its Ascent by the Contraction of the Diaphragm Here I cannot forbear making a Digression and presenting my Conjectures of the Use and Office of the Spleen since it ministers in this Part of the Animal Oeconomy The Arteria Splenica is not only very large in Proportion to the Magnitude of the Spleen but has a Remarkable Tortuous Passage to it Tab. 36. F. 1. whence we may conceive as the Quantity of Blood sent to the Spleen is very great so it s Impetus is very much Abated Next the Communications between the Extremities of its Arteries and Veins are very Large as appears by the Prompt Exit which Water pour'd into one Finds by the other and the Inflation of the Veins which is easily made by Blowing into the Arteries when the whole Spleen and its Veins become Distended with it The Lymphe-ducts of the Spleen we have Observ'd Tab. 36. Fig. 1. to Arise from the Vesiculae at the Extremities of its Veins and Discharge their Contents into the Neighbouring Lymphatick Glands whence it is sent into the Receptacule of the Chyle Its Nerves are Distributed thro' its whole Substance and serve to preserve its Tone and Regulate the Separation of its Lympha and Nutritive Juice But the most exact Scrutiny of Anatomists could never yet Discover any Excretory-duct arising from this Viscus and indeed the Patent Communication of its Vessels seems a convincing Proof that no such Excretory-duct can Exist but must appear very plain Besides it seems Extravagant and Unbecoming the Wonderful Providence of Nature to Separate any particular Juice in the Arteries here to be instantly Refunded into the Veins and we can hardly conceive the Blood can suffer any Alteration in a Place where the Transit from the one to the other is so Ample After these Considerations Premis'd if the Problem be Propos'd What can be the Design of the great Architect of our Bodies in the Fabrication of so Large and Remarkable a Part without any Fluid Secreted in it besides its own Nutritive Juice and Lympha I believe our Hypothesis will enable us to give a sufficient Reply to this seeming invincible Difficulty with which Learned Men have exceedingly perplex'd themselves I conceive then the Spleen is Design'd by Nature as a Diverticle to receive a large Proportion of Blood to be Refunded by its Veins into the Porta and promote the Reflux of the Blood Imported thither from the Stomach Guts Pancreas Mesentery c. by whose slow Progress thro' the innumerable Glands of those Parts it returns Thick and unfit for Motion And this seems but Necessary that a new Quantity of Blood charg'd with a Copious Serum should be Infunded into this Refluent Liquor before it Arrives at the Liver to dispose it to pass the Extremities of the Vena Cava and add a fresh Impetus to its Languid Motion caus'd by its Long and Tortutous Progress This I take to be the Use and Office of the Spleen and seems to have all the Circumstances the Laws of Mechanism require for this Purpose The Novelty of which Opinion will I hope be no Prejudice to its Reception in the Minds of Candid and Impartial Men. Having thus Represented the Circulation the Order of Nature leads us to Respiration which serves in conveying the Blood from the Right to the Left Ventricle of the Heart and Impregnates it with
Divers transverse strong Ligaments in the Lateral Sinus F F The Orifices of the Veins of the Brain in the Longitudinal Sinus G G That Part of the Dura Mater which adhered to the Lamdoidal Suture of the Skull H The Medulla Oblongata going out of the great Foramen of the Skull in the Os Occipitis I The Cerebellum cover'd with the Dura Mater Fig. 3. A Part of the Longitudinal Sinus opened B B c. The Veins of the Brain before they enter the Sinus C C Their Orifices opening into the Sinus variously some of them being parallel to their Trunks other Veins first pass in the Duplicature of the Sinus forwards and others backwards by which means the Progressive Motion of the Blood is not only assisted in some Positions of the Head and it s too rapid Motion prevented in others but a due Mixture and Reunion of its Parts are made after undergoing so elaborate a Strainer as that of the whole Substance of the Brain especially in its Cortical or Glandulous Part. Fig. 4. A A The Posterior and Lateral Part of the Brain covered with its Meninges B B The Os Petrosum broken off from the Cranium C Part of the Os Occipitis in like manner divided from the Skull D The Inferior and Tortuous Part of the Lateral Sinus on the Left Side opened in which may be observed its transverse strong Ligaments exprest Fig. 2. E. E The Cavity in the Os Petrosum or Specus which receives the Bulbous Part of the Lateral Sinus at the Beginning of the Jugular Vein F The Trunk of the Internal Jugular Vein G A Probe inserted into the Jugular Vein by the Sinus H The Bulbous Part of the Lateral Sinus which was contained in the Specus of the Os Petrosum Fig. 5. A A Part of the Lateral Sinus cut off B B A lacerated Portion of the Dura Mater which involv'd that Sinus expanded C The Bulbous Part of that Sinus which was contain'd in the Specus or Cavity of the Os Petrosum which is a Diverticulum to the Refluent Blood least it should too suddenly press into the Internal Jugular Vein D D D The Filaments of the Dura Mater broken off E The Beginning of the Internal Jugular Vein As the Structure of the Veins of this Part differ from that of others so also the Arteries of the Brain have a peculiar Organization at their Entrance from the ordinary Course of those of other Parts as does somewhat appear in the following Figure We have also Figured this Disposition of the Trunks of the Carotid Arteries finding them much more Tortuous than they are here represented Vid. App. Fig. 3.13 14. Fig. 6. A The Trunk of the Carotid Artery passing towards the Brain B C Part of its Membrane borrowed of the Dura Mater separated and expanded D D The lower Part of the Artery next the Heart The Vertebral Arteries also enter the Cavity of the Skull very much Contorted as appears in the Third Figure of our Appendix and again in the Eighth Figure where II shews their passing through the Transverse Process of the first Vertebra of the Neck K K their Trunks marching between the first Vertebra and Os Occipitis to the great Foramen of the last named Bone through which they pass into the Skull and afterwards conjunctly make up the Cervical Artery The Design of these Curvations in the Arteries before they enter the Cavity of the Skull is to prevent too great a Swiftness of the Current of the Blood through the whole Substance of the Brain which being placed so near the Heart would also suffer by its too great Pulsation were it not that the Contorted Trunks of these Arteries lessened its force else the frequent disorderly Motions of the Heart would make us as often incident to suffer great Inconveniences in the Brain yet nevertheless we are incident to suffer in some Degree whence 't is that the Passions of the Mind wherein the Heart is affected so suddenly disorders the Reason THE SEVENTH TABLE Fig. 1. REPRESENTS the Posterior Part of the Brain as it appears lying on the Basis of the Skull it s Upper Part being free'd from the Dura Mater A A The Hinder Lobes of the Brain raised and drawn somewhat forwards B C c. The Ligature and Two Pieces of Wood made use of for the better supporting the Brain in that Position D D Parts of divers Quadruplicatures of the Dura Mater E E A Division of the Second Process of the Dura Mater on the Left Side in which the Cerebellum appears F F The Cerebellum laid bare in that Division G H The Second Process of the Dura Mater on the Right Side intirely covering the Upper Part of the Cerebellum I I I The Edge of the Os Occipitis whence the Upper Part of the Skull is divided K K The Common Integuments of the Head turned off Fig. 2. The Inner Face of the Os Occipitis together with the Cerebellum c. A A The Cerebellum inclined forwards towards the Cella Turcica so that its Back Part which rests on the Os Occipitale comes in view B B The Hindmost Part of the Medulla Oblongata in its Passage out of the great Foramen of the Os Occipitis b The Processus Vermiformis of the Cerebellum C C C Divers Roots of the Eighth Ninth and Part of the Tenth Pairs of Nerves a a The Accessory Nerves accompanying those of the Eighth Pair at their Egress D D c. The Crassa Meninx or Dura Mater E E c. Part of the Edge of the Skull F F The Hairy Scalp diffected G Part of the Pericranium raised H The Left Ear. THE EIGHTH TABLE Fig. 1. IS Part of the Dura Mater together with the Falx dri'd A A The Falx supported so as to shew its proper Extent and Figure B B The Sinus Falcis Superior or Longitudinalis opened C The Sinus Falcis Inferior not distinguished in this Figure D D c. The Orifices of Veins opening into the Longitudinal Sinus and Trunks of other Veins going to it E The Beginning of the Longitudinal Sinus at the Os Crista Galli F F The Left Lateral Sinus G G G Two Parts of the Quadruplicatures of the Dura Mater lying between the Cerebrum and Cerebellum H H c. The Sticks Thread and Pins made use of to support the Membrane in drying it Fig. 2. Parts of the above mentioned Sinus distended with Wind and dried together with Part of the Dura Mater A The Longitudinal Sinus B B The Two Lateral Sinus's C The Fourth Sinus D A large Vein which empties its Blood at the Conjunction of the Four Sinus's which Union of the Sinus's is called Torcular Herophili Fig. 3. The Connection or Beginning of the Falx at the Os Crista Galli A The Os Cribrosum B The Crista Galli C A Portion of the Falx cleaving to the Crista Galli Fig. 4. Part of the Falx dried and exprest somewhat bigger than the Life A The Forepart of the
14. Represents in like manner a Portion of the Arteria Pulmonalis A A A The Three Sigmoidal or Semilunary Valves THE TWENTY-THIRD TABLE Fig. 1. REPRESENTS the External Coat of a Vein viewed with a Microscope A B C D The Fibres extended according to the Length of the Vessel where may be observed the Vasa Vasorum Fig. 2. A The Second Coat of the Vein called by Dr. Willis the Vasculous and Glandulous Coat Fig. 3. The Third or Internal Tunick of a Vein composed of Circular Fibres Fig. 4 The External Coat of an Artery consisting of a Rete of small Nerves A Blood-Vessels B and Membranous Expansions C On this Membrane of the Artery divers Glandulous Bodies appear composing greater and lesser Clusters D E variously dispersed Fig. 5. A B The Second Coat of an Artery consisting of divers Strata of Fibres variously decussating each other and joyned with the Internal or Third Coat Fig. 6. A B C The Inner and Smooth Surface of the Third or most Internal Coat of the Artery where the Foramina for the Branches which arise out of it are exprest and its Fibres extended according to its length B C. The great Trunks of the Arteries do evidently appear to consist of a greater Number of Strata of Fibres than those of the Veins but the farther they recede from the Heart they are both still more and more subdivided and their Trunks and Capillary Branches become still thinner and thinner till their outmost Extremities consist of one single transparent Membrane chiefly composed of such Tubes as only convey their Succus Nutritius And this I am apt to think may serve for the Description of Blood-Vessels in general and shall farther consider the Organization of the several Extremities of the Blood-Vessels in speaking of their particular Offices relating to Secretion in the several Parts wherefore at present shall only mention that the Extremities of Veins and Arteries are continued Channels variously contorted and not all of them of an equal Size even in Parts which are uniform or the same Vid. App. Fig. 4.5 After the Blood has past the Extremities of its Vessels and is in its Return to the Heart again by the Veins it there meets with divers Valves or Stops which prevent the Weight of the Blood of the Inferior Parts of the Body and the Recoiling of it in the Superior when any violent Motions affect the Thorax as in Coughing from pressing on the Extremities of the Vessels and hindering its progressive Motion That there is a Recoiling of the Blood in any extraordinary Motions of the Thorax in the Jugular Veins may be observ'd in taking Blood from thence especially in Children Hence it is the Valves in those Veins are necessary least the Blood should again repass into the Vessels of the Brain with great Violence which is also prevented in the Contortion made in the Internal Jugular Vein in its Specus in the Basis of the Skull I must confess I never yet observed above Two Valves one opposite to the other in the largest Vein that is furnished with Valves however Anatomists commonly mention Three and Professor Bidloo tells us of Four and Five Valves as they appear in the following Figures Fig. 7. Part of a Vein extended with Wind and dried having a double Valve or Two Valves of Semilunary Figures placed opposite to each other Fig. 8. A A A Portion of the Jugular Vein blowed up and dried B B B Its Three-fold Valves Fig. 9. Part of a Vein with Five Valves Fig. 10 11. A A The Portions of Veins exprest in the Two preceeding Figures lay'd open B B c. Their Valves as they appear in their Insides Fig. 12. The Valves as they appear in the Insides of the Veins according to Bidloo Fig. 13. Two Valves as they appear when taken out of the Veins Fig. 14. The unequal Distance of the Valves in the Veins the Vestigia of the Valves being here only exprest as they appear when the Vein is extended with Wind. Fig. 15. Represents according to Bidloo a System of the Arteries injected with Wax and free'd from the Body of an Infant Six Months Old which he tells us he has reserved If so it is a great Rarity indeed For having more than once free'd the Arteries from the Body of an Infant as well as from an Adult and finding them far differing from this Figure and not much disagreeing with the Descriptions and Figures of Vesalius and others I cannot look on this but as a Prodigy in Nature Wherefore I shall here give you his Description of it and refer you to my Appendix Fig. 3. Where their common Appearance is exprest as I now have them injected by me and dissected from the Body of an Infant The Arteria Aorta say's Bidloo arising from the Heart soon sends out Two small Coronary Branches B in the Body of the Heart It s Trunk is divided on the Pericordium into the Ascendens C and Descendens D. The First gives Branches to the Parts above the Heart and is divided into the Subclavii E from which the Axillares F and Internal Mammary G Three or Four Intercostales H and Cervicales I. do arise From the Axillary Artery are Branches communicated to the Scapula K and to the Superior Parts of the Thorax When it has got between the Muscles of the Cubit it is divided into Two little Branches the First of which L goes to the Wrist Thumb and Fore-Finger the other to the Three other Fingers It divides into Two about the Thymus and Forms the Carotides M. These ascending near the Wind-pipe after having sent several Branches to the Tongue Larynx and Parts adjacent and are divided into the External N and Internal Branch O the Exterior supplies the Face Lips partly the Ear and lower Teeth the other Branch serves the Forehead Temples and Neighbouring Parts The Inward Branch ascending streight through the Os Sphoenoides creeps under the ' Dura Mater and forming various Plexus's in that Part within the Skull it is cover'd with a particular Coat already describ'd it sends out small Branches near the Optick Nerves but the large Trunks creep back again sometimes united and by and by separated from each other There are small Branches convey'd to the Spinal Marrow partly above and partly below the Heart From the Axillarie's and ascending and descending Trunks it derives several Branches which reflected into a Circle creep through its Coverings and several Parts of the Head The descending Trunk of the Aorta D supply's some of the Intercostals 1 and the Neighbouring Muscles and Parts there is a large Trunk 2 also sent to the Diaphragm under the Diaphragm the Branches of the Viscera of the Abdomen are remarkable viz. of the Stomach 3. The Inferior and Superior Meseraic Branches 4 5 those of the Omentum or Caul 6 of the Liver 7 of the Kidneys 8 the Spermatics 9 and so on About the Os Sacrum this Trunk is divided into Two Branches from which others are again deriv'd to
if it is totally Obstructed a Deafness in which Case the Taking of Sneezing Powders gives Relief O The Glandulous Membrane Continu'd from the Foramina Narium to the Inside of the Fauces P P The Processus Scyloides Q The Carotid Artery Cut off near its Entrance into the Os Petrosum R R The Lower Parts of the Ossa Iugalia S A Cartilaginous Body lying in the Depressure of the Os Temporum where the Processus Condyliformis of the Lower Jaw is Articulated T The same Intermediate Cartilage of the Articulation Rais'd V The Smooth Sinus in the Os Temporale which Receiv'd the last mention'd Cartilage t Part of the Mucelaginous Gland of this Articulation Clearing to the above-mention'd Cartilage W The Upper Part of the Os Temporale Cut off X The Os Occipitis in like Manner Saw'd off Y The Musculus Occipitalis as it Arises from that Part of the Os Occipitis where the Muscles of the Head are Inserted whence Mounting it soon becomes Tendinous and Marches on the Sincipus where it 's Join'd with the Tendon of the Fromalis Unless it may be Suppos'd that the Occipital and Frontal Muscles are One Biventral Muscle Arising from the Occiput and Inserted to the Lower Part of the Skin of the Fore-head and being Fasten'd to the Hairy-scalp Moves it Forewards and Backwards as well as Lifts up the Lower Part of the Forehead with the Eyebrows Z Z The Thinner Part of the Os Occipitis where the Muscles of the Head are Inserted a The Gargareon Supported by the Probe N N Inserted into the Meatus à Palato ad Aurem b b The little Glandules which Appear in Cutting the Fauces from hence c c The Extremity of the Processus Pterygoides or more properly the Extremity of a Small Slender Process above the Processus Pterygoides in this Position of the Skull since Anatomists in Describing the Muscles of the Uvrela have call'd this Process Pterigoides or Aliformis we shall still Retain the same Name tho' the Aliform Process's Exprest Tab. 92. Fig. 2. K are Distinct Process's and no ways like these dd The Musculi Sphenopirrigostaphilini so call'd from their Origin Progress and Insertion they are also call'd Pterigopalatini and Sphenoterigopalatini they Arise Fleshy from an Acute Process of the Os Sphenoides Exprest Appen Fig. 15. H. whence they Pass to the Processus Pterygoides c c where they become Tendinous and are Reflected over those Process's to their Insertions on the Fore-part of the Gargareon When these Act they Draw the Fore-part of the Gargareus towards the Pterigoid Process's whereby it 's pull'd somewhat Upwards as well as Forewards e e The Sphenostaphilini These Arise from the same Process's of the Os Sphenoides with the former and are Inserted on the Back-part of the Gargareon Opposite to the Former These Draw the Uvula Upwards and Backwards whereby it Prevents the Ascent of the Aliment into the Foramina Nariton in Deglutition as it Happens in those in whom the Uvula is wanting f The Musculus Pterygoideus Externus Left at its Origin at the External Part of the Processus Pterygoides as well as the Upper Part of the Os Sphenoides it self whence it Passes Backwards to its Insertion at the Neck of the Processus Condyloides of the Lower-Jaw When this and its Partner Act they Draw the Lower-Jaw Forewards whereby the Fore-teeth of the Lower-Jaw are Driven beyond those of the Superior as Falloppius Observes g The Musculus Pterygoideus Internus also Free'd from the Lower-Jaw and Left at its Origin Tab. 15. Fig. 2. N. It 's Represented at its Insertion h Some Appearance of the Septum Narium Backwards i i The Denies Molares k k The Canini l The Inâ—isores m The Glandulae Labiorum as they Appear in the Inside of the Upper Lip Under the InInternal Membrane of the Mouth each of these Glands has an Excretory Duct which Perforates the Membrane of the Mouth at a small Papilla by which a Salival Humor is Emitted into the Mouth The like Glands may be seen on the Inside of the Cheeks n The Tip of the Nose o The Hairs of the Palpabrae Fig. 9. The External Surface of One of the Glandulae Tonfillae or Amigdalae where the many large Foramina of its Excretory Ducts Appear by which its Pituitous Matter is Discharg'd into the Fauces which joins with the Aliment in its Descent to the Gula. Fig. 10. The Receptaculum Chyli Fill'd with Quick-silver with the Neighbouring Lymphatick Glands remaining in their Proper Situation together with the Adjacent Parts as I could make a Sketch of them whilst I was Demonstrating the Parts of a Humane Body to some Worthy and Ingenious Gentlemen when Professor Bidloo favor'd me with a Visit. A A The Kidneys a a The Emulgent Veins of which that of the Right Side is Lower than the Left B The Ascending Trunk of the Vena Cava Distended with Wind the Lower Part of which is Comprest by the Iliack Artery of the Right Side b The Trunk of the Vena Cava Cut from its Entrance into the Liver and Ty'd C C Parts of the Two Iliack Veins which may be seen Distended with Wind below the Right Iliack Artery as the Vena Cava is above The External Iliack Veins as well as the Crutal Veins lie immediatly under the Trunks of the Arteries that Accompany them till they Pass by the Lower Part of the Musculus Triceps and Os Femoris to the Ham where the Vein is Uppermost and the Artery Passes Underneath after the same Manner the Great Trunks of Veins and Arteries do in other Parts This Contrivance in Nature of Placing the Trunks of the Iliack and Upper Parts of the Crural Arteries on the Veins is an Admirable Artifice to Accelerate the Ascention of the Blood to the Vena Cava and Heart as it Arises from the Inferior Parts by means of the Pulsation of the Arteries If you Inject the Arteries with Wax and afterwards Fill the Veins with the same you will see by the Figure of the Wax Contain'd in the Veins what Effect the Pulsations of the Arteries have on them in Order to Promote the Ascention of the Refluent Blood from below In this Compressure made by the Iliack Artery of the Right Side on the Inferior Part of the Vena Cava it s Contain'd Blood is Forc'd to Ascend towards the Heart the Valves in the Crural Veins Opposing its Descent By this means also the Pondus of the Refluent Blood from below is Lessen'd to the End its Motion may be the better Carri'd on at the Extremities of the Vessels in the Legs and Feet and a Kind of a Pulsation made by the Vena Cava whereby the Lymphatick Lumbal Gland R R lying between it and the Bodies of the Vertebrae is gently Comprest of which hereafter D D The Ascending Trunk of the Vena Cava below the Kidneys d d The Iliack Arteries E The Trunk of the Culiata Arteries Cut off F The Trunk of the Mesenterica